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alux_http_direct/
handler.rs

1//! Reaches one endpoint: it reads the arguments its roles state, applies the operation, and answers.
2
3use crate::input::DirectInputsAlg;
4use crate::input::{
5    DirectBodyInput, DirectCookieInput, DirectFormInput, DirectHeadInput, DirectHeaderInput, DirectMultipartInput,
6    DirectPathInput, DirectQueryInput, DirectRawBodyInput,
7};
8use crate::route::{DirectEndpoint, DirectRoute, DirectRouteImpl, DirectSelector};
9use crate::{DirectRequest, DirectResponse};
10use alux_ext::{ApplyAlg, HandlerContextAlg, OperationAlg};
11use alux_http::{
12    HandlerAlg, HandlerEndpointAlg, HttpInputAlg, HttpMethod, HttpSelectorAlg, OutputAlg, OutputKindAlg, RouteAlg,
13    RoutePath, SelectorAlg,
14};
15use std::sync::Arc;
16
17/// Interprets typed HTTP programs as a surface that answers requests itself.
18pub struct DirectHandlerImpl<Context> {
19    context: Arc<Context>,
20}
21
22impl<Context> DirectHandlerImpl<Context> {
23    /// Creates an interpreter owning a newly shared context.
24    pub fn new(context: Context) -> Self {
25        Self { context: Arc::new(context) }
26    }
27
28    /// Creates an interpreter from an existing shared context.
29    pub fn from_shared(context: Arc<Context>) -> Self {
30        Self { context }
31    }
32}
33
34impl<Context> HandlerContextAlg<Context> for DirectHandlerImpl<Context>
35where
36    Context: Send + Sync + 'static,
37{
38    type Handle = Arc<Context>;
39}
40
41impl<Context> HandlerAlg for DirectHandlerImpl<Context> {
42    type Endpoint = DirectEndpoint;
43}
44
45impl<Context> HttpInputAlg for DirectHandlerImpl<Context> {
46    type Path<I> = DirectPathInput<I>;
47    type Query<I> = DirectQueryInput<I>;
48    type Body<I> = DirectBodyInput<I>;
49    type Form<I> = DirectFormInput<I>;
50    type Multipart<I> = DirectMultipartInput<I>;
51    type RawBody<I> = DirectRawBodyInput<I>;
52    // A header, an authentication value, and an endpoint context are all read from what arrived
53    // before the body.
54    type Header<I> = DirectHeaderInput<I>;
55    type Cookie<I> = DirectCookieInput<I>;
56    type Auth<I> = DirectHeaderInput<I>;
57    type Context<I> = DirectHeadInput<I>;
58}
59
60impl<Context, Inputs, Args, Transform, Answering, Output>
61    HandlerEndpointAlg<Arc<Context>, Inputs, Args, Transform, Output> for DirectHandlerImpl<Context>
62where
63    Context: Send + Sync + 'static,
64    Inputs: DirectInputsAlg<Args> + Send + 'static,
65    Args: Send + 'static,
66    Output: Send + 'static,
67    Transform: OutputKindAlg<Self, Output, Transform = Answering> + Send + 'static,
68    Answering: OutputAlg<Output, Output = DirectResponse>,
69{
70    fn finish_handler<Handler>(&self, handler: Handler) -> <Self as HandlerAlg>::Endpoint
71    where
72        Handler: OperationAlg + ApplyAlg<Arc<Context>, Args, Output = Output> + Send + Sync + 'static,
73    {
74        let context = Arc::clone(&self.context);
75        let handler = Arc::new(handler);
76        DirectEndpoint::new(move |request: DirectRequest, captures: Vec<String>| {
77            let context = Arc::clone(&context);
78            let handler = Arc::clone(&handler);
79            Box::pin(async move {
80                let inputs = match Inputs::extract(&request, &captures).await {
81                    Ok(inputs) => inputs,
82                    Err(error) => return error.into(),
83                };
84                let output = handler.apply(context, inputs).await;
85
86                Answering::output(output)
87            })
88        })
89    }
90}
91
92impl<Context> SelectorAlg for DirectHandlerImpl<Context> {
93    type Selector = DirectSelector;
94
95    fn identity(&self) -> Self::Selector {
96        SelectorAlg::identity(&DirectRouteImpl)
97    }
98
99    fn compose(&self, first: Self::Selector, second: Self::Selector) -> Self::Selector {
100        SelectorAlg::compose(&DirectRouteImpl, first, second)
101    }
102}
103
104impl<Context> RouteAlg for DirectHandlerImpl<Context> {
105    type Route = DirectRoute;
106    type Selector = DirectSelector;
107    type Endpoint = DirectEndpoint;
108
109    fn initial(&self) -> Self::Route {
110        RouteAlg::initial(&DirectRouteImpl)
111    }
112
113    fn coproduct(&self, left: Self::Route, right: Self::Route) -> Self::Route {
114        RouteAlg::coproduct(&DirectRouteImpl, left, right)
115    }
116
117    fn precompose(&self, selector: Self::Selector, route: Self::Route) -> Self::Route {
118        RouteAlg::precompose(&DirectRouteImpl, selector, route)
119    }
120
121    fn lift(&self, endpoint: Self::Endpoint) -> Self::Route {
122        RouteAlg::lift(&DirectRouteImpl, endpoint)
123    }
124}
125
126impl<Context> HttpSelectorAlg for DirectHandlerImpl<Context> {
127    type Selector = DirectSelector;
128
129    fn http_method(&self, method: HttpMethod) -> Self::Selector {
130        HttpSelectorAlg::http_method(&DirectRouteImpl, method)
131    }
132
133    fn http_path(&self, path: &RoutePath) -> Self::Selector {
134        HttpSelectorAlg::http_path(&DirectRouteImpl, path)
135    }
136
137    fn http_prefix(&self, prefix: &RoutePath) -> Self::Selector {
138        HttpSelectorAlg::http_prefix(&DirectRouteImpl, prefix)
139    }
140}